Many times it happens that your friends go into invisible mode for several reasons but you think that the user is offline but there’s a simple and easy way where in you can find easily that whether user is offline or in invisible mode.
All you need to do is first download the Google Talk Client from www.google.com/talk/ and after installing and logging in to the G Talk client a list of friends will be shown. Remember to select all from the list by clicking on View option which is at the bottom.
After doing the above procedure, if you want to check if the user is online or invisible then click on the user to chat, if the message in the pop up chat window reads “XYZ is offline. You can still send this person messages and they will receive them the next time they are online.” Then it means that user is really offline and not invisible whereas if the pop up chat window reads “XYZ is offline” then the user is in invisible mode and is online.”
This is just a tip in regards to find whether the user is offline or online in invisible mode. The right hand side image shows that user is really offline whereas at the left hand side below you can see that user is online but is in INVISIBLE Mode.